Method of sweetening hydrocarbon products



Patented July 10, 1934 OFFECE METHOD OF SWEETENING HYDROCARBON PRODUCTS No Drawing. Application December 9, 1931,

Serial No. 579,995

3 Claims.

This invention relates to methods of sweetening hydrocarbon products, and particularly low boiling point oils such as gasolines, naphthas, and kerosenes.

The usual method of producing sweet (negative doctor test) gasolines, naphthas, and kerosenes is to agitate the petroleum product with sodium plumbite, and to then add a small quantity of sulphur and again agitate the mixture. After agitating, the doctor solution, sulphur, and

the reaction products, are removed from the oil by settling and washing with Water.

It is extremely difficult to remove all moisture and suspended matter from the oil when the foregoing treatment is conducted continuously and especially in cold weather.

Another objection to the old practice appears when an excess of sulphur is added during the sweetening process, as a product containing this sulphur will not conform to the requirement that the gasoline shall pass the A. S. T. M. corrosion test.

An object of this invention, therefore, is to provide a simple, complete and economical method of producing a sweet low boiling point hydrocarbon oil, such as gasoline, naphtha, kerosenes and similar products.

Another object is to provide a method of sweetening a low boiling point hydrocarbon oil wherein the use of objectionable substances, such as sulphur which imparts a corrosive property to the product, are unnecessary.

A further object is to obtain a finished product that is ready for shipment immediately after treatment, without requiring the operations heretofore involved in freeing the product from moisture and suspended matter.

With the foregoing and other objects in view, the invention comprises the novel method hereinafter specifically described to point out details of one form of the invention. However, it is to be understood that the invention comprehends changes, variations, and modifications which come within the scope of the claims hereunto appended.

To illustrate one form of my invention, I will hereafter describe a method including a specific combination of steps whereby all of the foregoing advantages can be obtained in the treatment of gasoline and similar products.

The sour product is first percolated through a column containing a material capable of removing hydrogen sulphide, such as brucite (Mg(OI-I) 2) The brucite particles are preferably of such size that they will not pack and obstruct the flow of oil through the column, but not so large that the oil may channel through the brucite without coming into intimate contact with the numerous particles of brucite. a

It is preferable to force the oil upwardly through the brucite, instead of pumping the oil into the top and allowing the same to percolate downward through the brucite.

The preliminary treatment of the product with brucite will remove the hydrogen sulphide and free sulphur which may be present and which, if not removed, would interfere with the subsequent treatment. In some cases the removal of hydrogen sulphide by the brucite may be aided by first passing the oil through water in order that the oil may contain a trace of moisture.

After the removal of the hydrogen sulphide by means of the brucite, the gasoline or other low boiling point hydrocarbon product may be agitated with a finely divided substance, such as clay, fullers earth or other suitable material, which is impregnated with a material capable of sweetening the gasoline after the removal of the hydrogen sulphide. I have found that finely divided earth, such as contact clay impregmated with cupric chloride is very efficient.

The resultant mixture of impregnated clay and oil is preferably agitated to insure an effective contact of the impregnated clay with the oil. The time of this agitation Will depend upon the quantity of sulphur compounds in the product being treated and the quantity of impregnated clay used. It usually requires from three minutes to about two and one-half hours to complete the treatment.

After the oil is sweet to a doctor test the impregnated clay is removed in any suitable manner. Removal of the impregnated clay by filtering through a filter press, such as a Sweetland press is very satisfactory.

Both the brucite and clay impregnated with cupric chloride may be reclaimed after they cease to give efiicient results. The brucite may be reclaimed by steaming and then drying. The cupric chloride impregnated clay may be reclaimed by m0 passing the necessary quantity of dry hydrochloric acid gas through the clay containing the cupric chloride.

As a more specific example, I will show how a straight run positive to a doctor test (sour) gasoline was treated in accordance with this invention.

A column was filled with brucite and the sour gasoline while in a substantially liquid condition was passed upwardly through the column of brucite to remove the hydrogen sulphide, at such a rate of flow that the gasoline was in contact with the brucite for 25 to 30 minutes. A yield at the rate of 1830 barrels of excellent A. S. T. M. corrosion test gasoline was obtained per ton of brucite.

The straight run positive doctor test gasoline,

which had the hydrogen sulphide removed, was

then agitated for two and one half hours with finely divided clay impregnated with cupric chloride, at the rate of 104 barrels of gasoline to one pound of impregnated clay. After agitation, the clay was filtered out of the gasoline.

The finished gasoline was free from moisture, suspended solids, had an excellent A. S. T. M. corrosion test and was negative (sweet) to a doctor test.

I claim:

1. The method of treating a sour low boiling point hydrocarbon oil in the class of gasolines, naphthas, and kerosenes, which comprises the preliminary step of percolating said oil while in a substantially liquid condition through brucite, thereby removing hydrogen sulphide from the oil, and thereafter sweetening said oil by subjecting it to intimate contact with finely divided material impregnated with cupric chloride, agitating the resultant mixture, and separating the impregnated material from said oil.

2. The method of treating a sour low boiling point hydrocarbon oil-in the class of gasolines, naphthas, and kerosenes, which comprises percolating said oil while in a substantially liquid condition through brucite to remove hydrogen sulphide and free sulphur from said oil, thereafter adding a finely divided earth impregnated with cupric chloride to said oil, agitating the resultant mixture a sufiicient time to complete the reaction, and separating the impregnated earth from said oil. a

3. The method of treating a sour low boiling point hydrocarbon oil in the class of gasolines, naphthas, and kerosenes, which comprises passing said oil through water to provide said oil with a trace of moisture, percolating said oil while in a substantially liquid condition through a column containing particles of brucite at such a rate of fiow that the oil is in contact with the brucite a sufiicient length of time to remove hydrogen sulphite and free sulphur from said oil, adding finely divided contact clay impregnated with cupric chloride to said oil, agitating the resultant mixture a sufficient time to complete the reaction, and separating the impregnated clay from said oil.

HARRY T. BENNETT. 

